Relay magnet suspension



Oct. 23, 1962 z. J. KRUZIC 3,060,355

RELAY MAGNET SUSPENSION Filed May 20, 1960 I3 24 23 l2 l4 ll 9 23 Fig. I

WITNESSES INVENTOR 9/4 [M Zelko J. Kruzic J BY W am/W fi ATTORNEY Unite btates 3,060,355 RELAY MAGNET SUSPENSION Zelko John Kruzic, New Brighton, Pa., assignor to Westinghouee Electric Corporation, East Pittsburgh, Pa., a corporation of Eennsylvania Filed May 20, 1960, Ser. No. 30,543 11 Claims. (Cl. 317195) This invention relates to electromagnetically operated devices, and more particularly to suspension means for the magnets of industrial contactors, or relays, used in electric systems of control, wherein the magnetic circuit includes a laminated armature and a multi-leg laminated core member.

A prior art relay, more particularly the prior art relay disclosed and claimed in the copending application of Gustav I akel, Serial No. 848,779, filed October 26, 1959, Contactor, provides a magnet core mounting or suspension, which permits satisfactory alignment with the movable armature on closing. The mounting features include at least six separate and distinct elements that cooperate in assembled relation to provide for the satisfactory alignment mentioned, but, upon removal of the base from the cover, all the pieces drop out and become scattered, or even lost, at the work area. The result is that the reassembly of the relay, particularly in the field, namely, in the customers plant away from assembly jigs, becomes rather diflicult.

One object of this invention is the provision of a structure for the suspension of the magnet core of a relay, or contactor, that retains the magnet core on the base in assembled relation when the base and cover are separated, and provides in use all the proper alignment features between magnet core and movable armature.

Another object of this invention is the provision of a magnetic circuit mounting in a relay that provides proper alignment of the movable parts to effect noiseless operation and which does not become disassembled by the removal of the relay cover.

It is a broad object of this invention toprovide a contactor that is compact, has a long noiseless useful life, and mere removal of the cover for inspection does in no way cause complete disassembly of parts.

It is also an object of this invention to provide mounting means for the magnetic core of a contactor for bolding the magnet core and retaining parts in positive working relation and which mounting means is both rigid enough to positively guide the core and resiliently movable enough to permit an adaptation of the position of the core to all the normal tilts and deflections the armature may undergo.

It is also an object of this invention to utilize shock absorption means for the magnetic core acting in a direction opposite to the attraction of the magnet core with respect to the armature.

These last recited objects of this invention are attained by using supporting means including a lever having reverse arcuate regions intermediate its ends, extending through the laminated magnetic core in a direction perpendicular to the direction of movement of the armature, said lever being held in balanced spring loaded position by means of springs cooperating with the ends of the lever at opposite sides of the laminated magnetic core, and abutting against some suitable stationary member on the base.

3,%ti,355 Patented Oct. 23, lean The objects recited are merely illustrative. Other objects and advantages will become more apparent from a study of the following specification and the accompanying drawing, in which:

FIG. 1, with parts in section, shows a front elevation of this invention;

FIG. 2, also with parts in section, shows a side elevation of this invention;

FIG. 3 shows a detail of one of the biasing springs; and

FIG. 4 shows a plan view, on an enlarged scale, of a slightly resilient cushioning member for the magnetic core.

The operating parts of the contactor are disposed in a housing 1 having the general shape of a right parallelopiped and comprising a bottom part, or base 2 and a top cover part 3, which parts are made of suitable molded insulating material, and which parts are firmly held together as a unit by suitable bolts disposed through apertured ears at diagonal corners of the housing. An E- shaped laminated main magnet, or core, 5 is disposed in the bottom part with the relatively long legs of the E projecting upwardly.

A magnetizing winding, or coil 6, disposed on a suitable spool 7 of insulating material, is disposed over the middle leg 8 of the core 5. Near the bottom 9 of the core 5, that is, near the mid-portion of the inner bottom of the part 2 when the core is in position, a relatively small rectangular hole, or opening, 10 is provided transverse- 1y through the core 5. A relatively narrow elongated, flat and relatively thin but quite stiff bar 11 rectangular in cross-section is disposed through the opening with the ends projecting beyond opposite sides of the laminated core 5.

The bar 11 has a downwardly directed bowed portion 12 near its mid-portion to engage the middle of the upwardly facing surface forming the bottom boundary of the hole 10. At each side of the bowed portion 12 the bar is provided'with upwardly directed bowed positions 13 and 14 which curve downwardly at the ends sufliciently so that the lower surfaces of the horizontal flat end portions 15 and 16 of the bar fall below the upwardly facing surface forming the bottom boundary of the hole 10. This construction aids in retaining the bar in the hole since it does not readily slide longitudinally. This is particularly true since the clearance between parts 13 and 14 and the top boundary of the hole 14 is made quite small. The bar 11 can only be inserted and removed from the slot, or opening, 10 by an end force sufiicient in magnitude to somewhat distort the bar temporarily during insertion and during removal of the bar 11.

The base 2 is provided with the ledges, or bridging members, 17 and 18. The downwardly directed surfaces of the bridging members 17 and 18 are provided with recesses 19 and 20 for receiving the springs 21 and 2,2. These springs 21 and 22, in the assembled-relation of the parts, engage the ends 15 and 16, respectively. The springs are selected to be rather stiff and are, when in position, under some loading and thus actuate the bar 11 downwardly and thus urge, or bias, the magnet core 5 downwardly. The upper ends of the springs 21 and 22 are readily held in the recesses in the bridging members 17 and 18. A thin layer of glue as 122, shown in FIG. 3, may also be used to hold the springs. This glue holds the springs in desired position when, for any reason, the bar 11, by longitudinal movement through either of the openings 30 or 31 in the base 2, is removed from the base and is thus of utility during assembly as Well as reassembly in the field.

The upwardly facing surface at the bottom of part 2 is provided longitudinally thereof with an arcuate ridge 23 in the shape of a relatively small segment of a cylinder. A flat rectangular strip 24, of elastomeric material, as fibreboard, or pressboard, or paper card-board, or hard rubber, or neoprene, or other equivalent somewhat resilient material, fits snugly in part 2 against the arcuate ridge 23 to engage this ridge in a line parallel to the axis of the ridge, or cylindrical segment 23.

The downwardly facing fiat surface of the core 5 longitudinally engages the strip 24. To better retain the strip in position it is provided with readily deformable ears 25 and 26 at the sides of the ends which thus abut against the inner surface of the side walls of base 2. This strip 24, while not an absolutely necessary part of this invention, aids in absorbing shock, and aids in suppressing noises.

Since the springs 21 and 22 are under loading the magnet is urged against the ridge 23 and all the parts, the base 2, the strip 24, the magnet 5, the bar 11 and the springs 21 and 22 are held together as a unit and do not become disassembled into separate and distinct items the moment the cover is removed.

From the foregoing description it is apparent that the bowed portion 12 contacts the bottom of the slot in a line contact that is in close proximity to the line contact of the core on the ridge 23 and is parallel to this contact line on the ridge 23.

The coil spool has a flat bottom resting on suitable ears protruding from the casing walls but could also be arranged to rest on the flat top surfaces of the bridging members 17 and 18. The upper end of the coil spool engages the top part 3 telescopically but against suitable shoulders. Thus when the diagonally disposed securing bolts are in firm position, then the coil spool is firmly held in position.

The upper part 3 houses the contact assembly, the contact-bridge carrier 27 and the armature 28 which may be a flat laminated bar but preferably is E-shaped with the E having relatively short legs. The legs are directed downwardly to engage the upwardly directed legs of the core 5. A through-bolt 29 fitting not too snugly pivotally mounts the armature on the contact-bridge carrier 27 so that the armature 28, within certain limits, has freedom of rotation in the plane of the paper, as shown in FIG. 2.

From the foregoing disclosure of the mounting of the core 5 in relation to the bottom part, the coil and the armature, it is apparent that the core, or magnet, 5, may, when necessary, perform tilting movements thus adjusting itself to the movement of the armature. Further, since the magnet is biased downwardly by the springs 21 and 22 and is not actually rigidly mounted in the housing, it actually, upon .energization of coil 6, has some slight temporary upward movement. The armature and magnet so to speak meet in mid-air thus cancelling some of the impact of the armature. Any excess impact plus the expansion of the slightly compressed springs 21 and 22 causes the magnet and armature, as an assembly, to be pushed back against the strip 24. This strip thus acts as a stop and cushion at the same time, and thus also acts as a noise suppressant. The contactor of this invention has been found to be far less noisy since it is self-aligning.

Furthermore, it is not only possible to mount the core 5 so as to permit it to perform certain tilting movement relative to the coil and housing by means of the bar 11 and associated parts and the arcuate ridge, but it is also possible to support the coil spool relative to the top part of the housing by means of suitably positioned aligning extensions having the shape of rounded fins.

The contact-bridge carrier 27 is provided with suitable 4 structure for holding the moving contacts that are to coact with the stationary contacts.

The resetting of the armature and therefore the contact-bridge carrier is effected by diagonally displaced springs 37 and 38 which abut against the coil spool and the contact-bridge carrier. These springs are held in their recesses by a thin film of glue.

Since the contact structures are not part of this invention no detailed description need be given in this disclosure, however, reference may be had to the copending patent application hereinabove mentioned.

While but one embodiment of this invention has herein been described and shown in the drawings, various modifications are possible all falling within the spirit and scope of this invention.

I claim as my invention:

1. In an electromagnetically operable contactor, in combination, a base, a laminated core in said base, said core having upwardly directed projecting means, coil means mounted on said projecting means, an armature movable by the energization of said coil means toward said projecting means, a coil retaining member in the form of a bar, said bar extending through the laminated core in a direction perpendicular to the direction of movement of the armature, and being supported at both ends by springs coacting with the bar at both ends at the sides of said laminated core and abutting against a stationary member on the base, said springs thus biasmg said cor-e against a pivoting surface on the base to provide pivotal movement for the core on the base and to retain the core in the base.

2. In an electromagnetically operable contactor, in combination, a generally cup-shaped base having a generally rectangular bottom, a curved ridge disposed in the bottom of the base running from one end wall to the other and the top of the ridge being substantially equally spaced from the other two walls, a laminated core in said base and having a flat bottom surface resting on said ridge, said core having upwardly directed projecting means, coil means mounted on said projecting means, an armature movable by the energization of said coil means toward said projecting means, a core retaining member in the form of a bar, said bar extending through the laminated core in a direction perpendicular to the direction of movement of the armature, and being supported at both ends by springs coacting with the bar at both ends at the sides of said laminated core and abutting against a stationary member on the base, said springs thusbiasing said core against a pivoting surface comprising said ridge on the base to provide pivotal movement for the core on the base and to retain the core in the base.

3. In an electromagnetically operable contactor, in combintaion, -a magnetic circuit including a core and an armature, spring means for biasing the armature out of contact with the core, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other, said core having a flat outer face remote from the surface engaging the armature, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge facing the flat outer face on the core, said core having a transverse opening a relatively short distance from the flat outer face, a bar disposed through said opening with its ends projecting beyond the core and having an arcuate surface intermediate its ends engaging one boundary of the opening in the core in facing relation to said ridge, and biasing spring means disposed between parts of the base and the ends of the bar to bias the bar and thus the flat surface of the core against said ridge.

4. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface, spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, said core having a flat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the flat outer face on the core, said core being provided with a transverse opening rectangular in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the fiat outer face on the core and the shorter sides falling in planes perpendicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening, said bar at its mid-region having a downwardly directed curve to engage the mid-region of the opening, two ledges on the base facing the respective ends of the bar on the sides remote from the curved surface engaging the mid-portion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar, whereby the base, core, bar and springs are held together as a unit and the core is biased against hte ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so htat the armature and core engage during each operation over their entire flat engaging surfaces.

5. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface, spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, 'siad core having a fiat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the fiat outer face on the core, a flat elongated strip of elastomeric material disposed against the ridge to engage it with a line contact, the flat outer face of the core resting against the strip of material, said core being provided with a transverse opening rectangular in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the flat outer face on the core and the shorter sides falling in planes perpendicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening, said bar at its mid-region having a downwardly directed curve to engage the midregion of the opening, two ledges on the base facing the respective ends of the bar on the sides remote from the curved surface engaging the mid-portion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar, whereby the base, core, bar and springs are held together as a unit and the core is biased by said springs through said strip of resilient ma terial against the ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so that the armature and core engage during each operation over their entire flat engaging surfaces.

6. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface,

spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, said core having a flat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a Well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the flat outer face on the core, said core being provided with a transverse opening rectangular in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the flat outer face on the core and the shorter sides falling in planes perpindicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening, said bar at its mid-region having a downwardly directed curve to engage the mid-region of the opening, said bar at each side of the curve at the mid-region being provided with an upwardly directed curve sufficient in extent to be in close proximity to the top surface of the opening in the core, two ledges on the base facing the respective ends of the bar on the sides remote from the curved surface engaging the mid-portion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar, whereby the base,

core bar and springs are held together as a unit and the core is biased against the ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so that the armature and core engage during each operation over their entire flat engaging surfaces.

7. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface, spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, said core having a flat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the flat outer face on the core, said core being provided with a transverse opening rectangularly in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the flat outer face on the core and the shorter sides falling in planes perpindicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening, said bar at its mid-region having a downwardly directed curve to engage the mid-region of the opening, said bar at each side of the curve at the mid-region being provided with an upwardly directed curve sufficient in extent to be in close proximity to the top surface of the opening in the core, and the ends of the bar being bent down wardly so that the bottom face is parallel to the bottom of the opening but falls somewhat below the bottom of the opening, two ledges on the base facing the respective ends of the bar on the sides remote from the curved surface engaging the mid-portion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar, whereby the base, core, bar and springs are held together as a unit and the core is biased against the ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so that the armature and core engage during each operation over their entire flat engaging surfaces.

8. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface, spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, said core having a flat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the flat outer face on the core, a flat elongated strip of elastomeric material disposed against the ridge to engage it with a line contact, the flat outer face of the core resting against the strip of material, said core being provided with a transverse opening rectangular in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the flat outer face on the core and the shorter sides falling in planes perpendicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening, said bar at its mid-region having a downwardly directed curve to engage the mid-region of the opening, said bar at each side of the curve at the midregion being provided with an upwardly directed curve sufiicient in extent to be in close proximity to the top surface of the opening in the core, two ledges on the base facing the respective ends of the bar on the sides remote from the curved surface engaging the mid-portion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar, whereby the base, core, bar and springs are held together as a unit and the core is biased through said strip of resilient material against the ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so that the armature and core engage during each operation over their entire flat engaging surfaces.

9. In an electromagnetically operable contactor, in combination, a magnetic circuit including a core and an armature, said core having an armature engaging surface, spring means for biasing the armature away from the armature engaging surface, a coil for magnetizing the magnetic circuit to cause said armature and core to move toward each other into engaging relation, said core having a flat outer face remote from said armature engaging surface and substantially parallel to the armature engaging surface, a base having a well for receiving the core, said base at the bottom of the well having an elongated ridge, generally in the shape of a segment of a cylinder, facing the flat outer face on the core, a flat elongated strip of elastomeric material, provided with retaining ears at its ends engaging the end walls of the well of the base, disposed against the ridge to engage it with a line contact, the flat outer face of the core resting against the strip of material, said core being provided with a transverse opening rectangular in section spaced a relatively short distance from the flat outer face of the core, with the longer sides of the opening being substantially parallel to the flat outer face on the core and the shorter sides falling in planes perpendicular to the ridge axis, a bar rectangular in cross-section and longer than the length of the opening disposed in said opening so that the ends project from each end of the opening,

8 said bar at its mid-region having a downwardly directed curve to engage the mid-region of the opening, two ledges on the base facing the respective ends of the bar on the sides remote from the curvedsurface engaging the midportion of the opening, a spring, under any selected value of compression, which value may include a zero value, disposed between one ledge and one end of the bar and a similar spring similarly under compression disposed between the other ledge and the other end of the bar,

whereby the base, core, bar and springs are held together as a unit and the core is biased through said strip of resilient material against the ridge, yet, upon energization of the coil, the core is free to move toward the armature by a small distance and will tilt to a set position so that the armature and core engage during each operation over their entire fiat engaging surfaces.

10. In an electromagnetically operable device, in combination, a base hollowed-out to provide a well, an elongated, straight, upwardly directed convex ridge in the bottom of the well, a magnetic circuit comprising a core disposed in the well to rest on said ridge to make line contact with said ridge, a movable armature disposed to coact with said core, said core having upwardly directed projecting means having armature engaging surfaces, coil means operatively disposed with respect to said magnetic circuit, said armature being mounted for pivotal movement about an axis above said ridge transverse of the ridge and for translational movement toward said projections upon energization of said coil means, said core being provided with a transverse slot near its bottom surface, core retaining means comprising a bar, having a downwardly directed bowed portion near its middle, disposed in said slot so that the bowed portion engages the bottom of the slot and the ends project beyond the core at each side of the core, said bar having upwardly bowed portions, at each side of the downwardly directed middle bowed portion, of sufiicient magnitude that the crest of each bowed portion is in close proximity to the ceiling portion of the slot, the contour at the outer portions of the upwardly directed bowed portions being such that the outer ends of the bar project normally from the core and the lower surfaces of the projecting ends fall somewhat below the bottom of the slot, whereby the bar is retained in the slot and can only be inserted and removed from the slot by an end force sufiicient in magnitude to somewhat distort the bar temporarily during insertion and during removal of the bar, a spring receiving ledge in one inner side wall of the well, a second spring receiving ledge in the inner opposite side wall of the well, a spring disposed between one ledge and one projecting end of the bar, a second spring disposed between the other ledge and the other projecting end of the bar, whereby the core bottom is biased against the arcuate ridge and thus has some freedom of pivoted adjusting movement on the ridge and is retained in the well of the base.

11. In an electromagnetically operable device, in combination, a base hollowed-out to provide a well, an elongated, straight, upwardly directed convex ridge in the bottom of the well, a covering of elastomeric material of substantially uniform thickness disposed on said ridge, a magnetic circuit comprising a core disposed in the well to rest through said elastomeric covering on said ridge to make line contact with said ridge, a movable armature disposed to coact with said core, said core having upwardly directed projecting means having armature engaging surfaces, coil means operatively disposed with respect to said magnetic circuit, said armature being mounted for pivotal movement about an axis above said ridge transverse of the ridge and for translational movement toward said projections upon energization of said coil means, said core being provided with a transverse slot near its bottom surface, core retaining means comprising a bar, having a downwardly directed bowed portion near its middle, disposed in said slot so that the bowed portion engages the bottom of the slot and the ends project beyond the core at each side of the core, said bar having upwardly bowed portions, at each side of the downwardly directed middle bowed portion, of sufficient magnitude that the crest of each bowed portion is in close proximity to the ceiling portion of the slot, the contour at the outer portions of the upwardly directed bowed portions being such that the outer ends of the bar project normally from the core and the lower surfaces of the projecting ends fall somewhat below the bottom of the slot, whereby the bar is retained .in the slot and can only be inserted and removed from the slot by an end force sufiicient in magnitude to somewhat distort the bar temporarily during insertion and during removal of the bar, a spring receiving ledge in one inner side wall of the well, a second spring receiving ledge in the inner opposite side wall of the well,

a spring disposed between one ledge and one projecting end of the bar, a second spring disposed between the other ledge and the other projecting end of the bar, whereby the core bottom through the elastomeric covering is biased against the arcuate ridge and thus has some freedom of pivoted adjusting movement on the ridge and is retained in the well of the base.

References Cited in the file of this patent UNITED STATES PATENTS 2,431,377 Durbin et a1. Nov. 25, 1947 2,584,707 Jarvis et a1. Feb. 5, 1952 2,671,187 Jencks Mar. 2, 1954 

